We wish to examine electron transfer characteristics of Fe-S proteins including ferredoxins, hydrogenase, glutamate synthase, and to develop pulsed EPR techniques for structural studies of paramagnetic enzymes. We propose to study both the activation (by ACTH) and mechanism of P450scc in adrenal cortical mitochondria. We use EPR, Mossbauer, and optical spectroscopy in this work. We have also uncovered a novel phenomenon, namely Cu ion 2 uptake and processing by lymphocytes entering blastogenesis. We propose to explore the biochemical basis of this early event in secondary immune response.